The present invention relates to a process for the production of rumen bypass feed supplements that are useful as an energy source for ruminants. The process converts fatty acid glycerides or a mixture of fatty acid glycerides and free fatty acids to the respective calcium salts. The present invention also relates to processes in which animal and vegetable fats and oils and their by-products from the food industries such as meat-packing and restaurants, containing high amounts of glyceride or free fatty acids, are employed in the formation of fatty acid calcium salts.
Conventional cattle feeds such as corn and alfalfa often fail to provide sufficient energy for cattle, especially lactating dairy cattle during periods of heavy milk production and cattle in the last trimester before calving, when nutrient needs are increasing. Feed containing a high proportion of corn also has a tendency to depress the milkfat content of the milk produced by such cattle. Fat is an excellent energy source, and it is known that if the proportion of fat in cattle food is increased, lactating dairy cattle produce higher milk yields without draining their reserves of body fat and without diminishing the proportion of milkfat in the milk produced.
However, it has been found that if the proportion of fat in the diet of cattle exceeds about 2% of the total feed in solids, the feed has toxic effects upon the microorganisms in the rumen of the cattle. The rumen, the largest of the four stomach compartments of ruminants, is the site of digestive breakdown of ingested foodstuffs. Absorption by the animal, however, takes place further along in the alimentary tract, principally in the abomasum and intestines. Although the rumen endows the animal with the capacity to digest and utilize cellulose effectively, it is relatively inefficient in the digestion and utilization of dietary fats.
Furthermore, fats apparently reduce the growth rate or even kill the microorganisms that digest fiber in the rumen, thereby lowering cellulose digestibility. This deleterious effect on the rumen is particularly true of unsaturated fats. In addition to reducing the growth rate or killing cellulose-digesting microorganisms, triglycerides and free fatty acids can physically coat fibrous or cellulosic material in the rumen and thereby inhibit fermentation of the material by the bacteria. This has an adverse effect on the total digestibility of the diet, and can result in a reduced yield of milk and butterfat.
U.S. Pat. No. 4,642,317 describes the incorporation of insoluble fatty acid salts in ruminant feed as a means of increasing the fatty acid content without deleteriously affecting the ruminant digestion cycle. A feed additive such as a fatty acid calcium salt functions as a rumen bypass product, and is subsequently metabolized in the abomasum small intestine of the ruminant.
Producing fatty acid calcium salt products that are free-flowing granular powders is desirable, so that the product can be easily transported and used in feed rations. This physical form of a fatty acid calcium salt allows for the addition to the feed rations by simple blending with the remaining ingredients.
The critical properties required for a granular material to be free flowing are that it be tack-free, non-cohesive and have a low dust content. Otherwise, the product will tend to lump, agglomerate, and generate dust in the surrounding environment. The product should also experience minimal particle segregation that would result in a non-homogenous feed ration. It should also be stable from oxidative rancidity.
One way to obtain a free-flowing product is to employ a low glyceride content fatty acid feedstock. This is disclosed in U.S. Pat. No. 5,382,678. This requires intermediate and costly processing of fats and greases to reduce the glyceride content.
It would be preferable to directly produce free-flowing granular fatty acid calcium salt rumen bypass feed products from high glyceride content materials such as yellow grease, white grease, lard and tallow or other animal and vegetable fats and oils. These materials are relatively inexpensive byproducts of the food industry and restaurant trade. The aforementioned U.S. Pat. No. 5,382,678 discloses a process for producing low glyceride content fatty acid calcium salts in the form of tackless free-flowing granules by reacting a fatty acid mixture with a basic calcium compound in an aqueous suspension. However, a reduced glyceride content fatty acid distillate must be employed as the starting material.
There remains a need for a process by which fatty acid calcium salt rumen bypass feed supplements may be produced in free-flowing granular form from relatively inexpensive grease and fat byproducts.